Currently, clinically useful systems for mapping body characteristics, such as temperature or pressure within the human body, provide only crude resolution. Invasive methods, including the use of catheters, often require hospitalization, gather data slowly or are expensive. U.S. Pat. No. 5,749,364 entitled xe2x80x9cMethod and Apparatus for Mapping Pressure and Tissue Propertiesxe2x80x9d describes the use of contrast-agent micro-bubbles to image a body characteristic. The contrast agent""s acoustic spectral behavior can be related to ambient pressure, as imposed, for example, by the pumping heart and surrounding blood. These approaches have limited accuracy. The data varies as a function of the variation in the properties of the contrast agent microbubbles. Such properties include composition, mean size, mean stiffness, etc. For example, their size variesxe2x80x947 microns diameter plus or minus 3 microns (2 sigma). The contrast agent""s material properties are difficult to control. Further the amount of information available from the contrast agent is limited.
Radio frequency (xe2x80x9cRFxe2x80x9d) identity-card devices and micro-tags can be inserted under the skin of a pet. These tags currently merely transmit an identification signal that uniquely identifies the animal. They are too large to be used for measuring parameters throughout a tissue volume such as temperature or pressure.
Micro-instruments suitable for medical diagnostic imaging of body parameters are provided. Each micro-instrument has an observable property that varies as a function of a physiological property, such as temperature or pressure. For example, the observable property comprises an identifiable acoustic response. Based on the acoustic response, an image, a quantity or a combination thereof is generated.
In a first aspect, a micro-mechanical device for admission into a body and for communicating medical diagnostic information is improved. The improvement comprises a leadless micro-instrument particle having an observable property that varies as a function of a physiological property.
In a second aspect, a medical diagnostic ultrasound system for observing a physiological property of a body is provided. The system includes a transmit beamformer operable to transmit ultrasonic energy into the body. A micro-instrument particle has an observable property responsive to the ultrasonic energy where the observable property varies as a function of the physiological property of the body.
In other aspects, methods of use of a micro-instrument particle having an observable property that varies as a function of a physiological property are provided.